German Chancellor Angela Merkel on Saturday warned countries against going it alone, saying the only way to solve global problems is to work together.

“In a year in which we see unimaginable challenges we can either work together or retreat to our individual roles. I hope that we will find a common position,” Merkel told a security conference audience including US Vice President Mike Pence in Munich.

Pence is expected to spell out what US President Donald Trump’s “America First” policy means for the rest of the world.